In a rare piece of good news for the company, the new Boeing 777X has taken to the skies for first time as it enters the next phase of its test program.

Based on the 777 and with proven technologies from the 787 Dreamliner, the 777X took off in front of thousands of spectators at Paine Field in Everett, Washington, for a near four-hour flight.

“The 777X flew beautifully, and the testing was very productive,” said Van Chaney, 777/777X chief pilot for Boeing.

“Thank you to all the teams who made today possible.”

Chaney and Boeing chief pilot, Craig Bomben, worked through a detailed test plan to exercise the plane’s systems and structures while the test team in Seattle monitored the data in real time.

“Our Boeing team has taken the most successful twin-aisle jet of all time and made it even more efficient, more capable and more comfortable for all,” said Stan Deal, president and chief executive of Boeing Commercial Airplanes.

The first of four dedicated 777-9 flight test airplanes, WH001 will now undergo checks before resuming testing in the coming days.

The test fleet, which began ground testing in Everett last year, will endure a comprehensive series of tests and conditions on the ground and in the air over the coming months to demonstrate the safety and reliability of the design.

Boeing expects to deliver the first 777X in 2021, with Emirates the launch customer.

The program has won 340 orders and commitments from carriers around the world, including ANA, British Airways, Cathay Pacific Airways, Etihad Airways, Lufthansa, Qatar Airways and Singapore Airlines.